Concrete pile form with pneumatically expansible and contractible removable drive core



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CONCRETE PILE FORM WITH PNEUMATICALLY EXPANSIBLE AND CONTRACTIBLE REMOVABLE DRIVE CORE 5 Sheets-Sheet 4 Filed Feb. 24, 1959 INVENTOR. JOHN J Kl/PKA' July 3, 1962 3,041,839

J. J. KUFKA CONCRETE FILE FORM WITH PNEUMATICALLY EXPANSIBLE AND CONTRACTIBLE REMOVABLE DRIVE CORE Q 676W P/TfS'SZ/FE /9//? IN VENTOR. fay/v f/fz/fi/mv Mzm.

United States Patent 3,041,839 CONCRETE PILE FORM WITH PNEUMATICALLY EXPANSIELE AND CONTRACTIBLE REMOVA- BLE DRIVE CORE John J. Kupka, Gladstone, N.J., assignor to McKiernan- Terry Corporation, Harrison, N.J., a corporation of New Jersey Filed Feb. 24, 1959, Ser. No. 795,036 8 Claims. (Cl. 61-53.72)

The invention herein disclosed relates to concrete pile forms of the type covered in copending patent application Serial No. 709,604, filed January 17, 1958, issued February 28, 1961, as Patent No. 2,972,872 wherein the shell which provides the form for the concrete is driven by a split tube that is expanded into gripping engagement with the shell for drive purposes and is contracted to efiect separation from the shell when the core is to be withdrawn from the driven shell. 1

In that patent a system of wedge cams and toggles is provided for etfect-ing the expansion and contraction of the split drive tube.

The present invention utilizes the principle of the split drive tube but involves a substitution of pneumatically actuated means for effecting expansion and contraction of the drive tube in place of mechanical means such as mentioned.

The use of pneumatic means results in fewer parts and less complication and has other advantages over a mechanical system.

Other desirable results attained will appear as the specification proceeds and further objects of the invention also will become apparent.

A special object that is particularly important has been to make certain that in the event of any failure in the pneumatic system warning will be given orthe machine may be shut down, thus to avoid injury to equipment or personnel should failure occur which would not nor- -mally be immediately apparent.

,tional views of the upper and lower ends respectively of a concrete pile form embodying the invention.

FIGS. 3, 4 and 5 are similar views of these parts taken on a plane at right angles to the plane of FIGS. 1 and 2 and omitting the outer shield.

FIG. 6 is an outside view of thecompletepile form, broken to indicate the variable length of the structure.

FIG. 7 is a horizontal sectional view on substantially. the plane of line 77 of FIG. 1 showing the transverse key provided to tie the'head parts of the form together and to suspend it from the pile hammer used to drive the form.

FIGS. 8 and 9 are cross sectional views on substantially the planes of lines 88 and 99 of FIG. 1 showing on a larger scale the contracted and expanded relation of the parts.

FIG. 10 is a partly sectioned perspective view of upper and lower core sections showing how these sections are joined by companion pin and socket coupling elements on opposite ends of the center pipes which carry the expansion sleeves.

FIG. 11 is a diagrammatic view illustrating the safety warning and control system.

FIG. 12 is a broken sectional detail of the diflierential pressure valve serving in this instance to operate a warning signal.

In the several views the shell of the form is designated ice 15 and it is shown as having a driving point 16 engaged by a drive head 17, FIG. 2, on the lower end of the removable core.

At the top the core is provided with a driving head 18 by which it is connected with the power hammer, FIG. 1, showing how this is accomplished by a cross key 19 extending through slots 20 in the head and having its ends connected with cables 21 which are looped up over the top of the hammer structure indicated at 22.

The driving head 18 is shown in FIG. 1 as having a cushion 23 of wood or-other suitable material seated in the top of it and as open at the bottom at 24 to accommodate the drive cap 25 in the upper end of 'the core.

The drive head 18 is finished with a drive shoulder 26 in engagement with the upper end of drive cap 25.

The drive cap 25 as shown in FIG. 1 bears upon the upper end of the split drive tube 27 and the latter, as shown in this view, is disposed within the shell and carries a sleeve of rubber-like gripping material 28 engageable with the shell.

Slots 29 in the sides of the drive cap providefree passage for the key 19 and allow for necessary freedom of movement between the parts.

The pneumatic expansion means comprises an annular expansion bag or tube 30 fitted to the Wall of the split tube and carried by a center pipe 31 ported at 32, FIG.

'1, to supply air to and release it from the expansion bag.

The center pipe 31 has an annular head orring 33 at the top, FIG. 1, slotted at 34 for loose passage of the supporting key 19.

The center supply pipe 31 is thus hung on the through key 19, supporting the air bag in position for engagement with the drive tube, independently of the drive head and split drive tube and the drive head 18 and the drive cap 25 by reason of the slots 20 and 29 have limited movement independent of the center pipe.

The upper end of the center supply pipe is shown closed by a plug 35, FIG. 1, which may be secured by anoverstanding snap ring inserted in the groove 36. This plug is shown as having an enlarged slot 37 for the key 19 and as provided with a screw socket 38 normally closed by screw plug 39 and which after removal permits engagement of a screw threaded lift rod for pulling the plug out of the socketed end of the center pipe.

The center plug 35 is sealed air-tight as by a sealing ring inserted in the surrounding groove 40, FIG. 1.

Compressed air is supplied to and exhausted from the center pipe through pipe or tube connections indicated at 41 in FIG. 1.

The air bag 30 is shown as secured at opposite ends on the center pipe by clamp bands 42 engaged over reduced neck portions at the ends of the bag.

To avoid possible endwise creepage these clamps are abutted against fixed shoulders on the pipe.

The upper clamp 42 is shown in FIG. 1 as engaged against the lower end of the pipe head or sleeve 33 and the clamp 42 at the lower end, appearing at the top in FIG. 2, the latter considered as an extension of FIG. 1, is shown as abutting against a flange or ring 59 on the lower end of the pipe.

To avoid extrusion of the end walls of the bag, supporting rings 44 beveled or rounded to fit the shoulders at the ends of the bag are held by the clamps in engagement or approximate engagement with these end wall portions of the bag.

For a relatively short concrete pilesuch as about twenty feet the expansion bag and center pipe may be all in a single unit, one length of bag and one length of pipe.

In such event the lower end of the center pipe is sealed 0E and seated in the lower drivingbead 17 as shown at the bottom in FIG. 2.

This is accomplished through the provision of a plug and pin forming extension 45 on the lower end of the center pipe 31 which fits in the socket 46 in the drive head 17, seating on a cushion 47 at the bottom of that socket.

The parts are pinned in this relation by a cross key 48 extending through registering slots in the pipe extension 45 and drive head 17, the slots in the latter being enlarged as indicated in broken lines in FIG. 2 to permit the limited independent movement of pipe and drive mechanism hereto-fore explained.

This cross pin or key 48 is shown held in place by a surrounding retainer ring 49 seated in the groove in the drive head.

Ports 51 through the extension 45 are shown in FIG. 2 as closed by screw plugs 52.

FIG. 3 illustrates the single length drive section, connected at the top with the drive head 18 and having the pin extension 45 of the center pipe at the bottom directly engageable in the drive point 17.

If longer piles are to be driven, say on the order of forty or sixty feet, separate top and bottom sections will be used with one or more intermediate sections connected between them.

To provide for such requirements the top, bottom and intermediate sections of the pile form are preferably made with interchangeable pin and socket connections, that is with the socket forming sleeve members 33 on the upper ends of the center pipes and the companion pin projections 45 on the lower ends of the center pipes.

Also where sections are joined together in end to end relation, blow transmitting collars 53 are interposed between the opposing ends of the drive sleeves of those sections as shown in FIGS. 2, 4 and 5.

These intermediate drive collars 53 are shown as shouldered at 54 at one end to center in the drive tube of the adjoining section at that end and as held in place on the center pipe by cross pin or key 55 held against displacement by a surrounding retainer ring 56.

These drive rings or collars 53 may be similar in construction to the drive cap 25, FIG. 1, at the head of the form, having a passage therethrough to slidingly receive the upper end socket extension 33 of the center pipe but difiering otherwise, as shown in FIG. 5, in that they are slotted at 57 to hold the transverse keys 55 and, in these intermediate installations the slots '58 in the center pipe extensions 33 are elongated to allow limited freedom between the center pipe structure and the driving part of the column as represented by the split drive tubes and drive rings 53 between them.

Stop rings 59 held by snap rings 60 are mounted on the center pipe extensions where needed to prevent endwise creep of the air bags and these may be of a size to act as centering disks and dirt guards.

FIGS. 6 and 7 show the pile form with the driving head attached to the same by the cross key, ready for connection to the power hammer.

The cross sectional views, FIGS. 8 and 9 show how the air bags may be thickened or otherwise reinforced at 61 across the split in the drive tubes so that under pressure, FIG. 9, they will not extrude through the widened gap.

These views also show how the drive tube may be formed with an integral hinge portion opposite the split by grooving it longitudinally at 62. This provides a I desirable spring hinge effect enabling the tube to evenly expand under pressure of the air bag and to contract with release of pressure.

Other forms of integral spring hinge constructions may be provided.

Thus, as shown in FIG. 10, the drive tube, here designated 27a, may be longitudinally slotted opposite the split in longitudinally aligned lengths 63, separated at adjoining ends by continuous bridge portions 64 which serve as integral spring hinge knuckles, yielding to permit expansion and applying spring force to close the tube on release of pressure.

The ends of these hinge slots are shown as enlarged at 65 to form. terminals relieving strain and avoiding possible fracture at these points.

The hingedly connected sections of the split tube provide a subsstantially continuous interior surface for the air bag to act upon and this extended area of contact enables satisfactory operation at reasonably low pressures.

The longitudinally coupled sections of the core are interchangeable so that they may be made up as a standard expansible section having companion pin and socket coupling elements at opposite ends enabling it to be used as a single section joined at the top to the driving head and at the bottom to the driving shoe or to be joined interchangeably to one or more other such sections.

The transverse keys form simple substantial means for detachably securing the sections together and to the drive head, drive point and the driving rings which are interposed between adjacent ends of the split drive tubes.

To prevent damage or injury in case of failure of the air supply the expansible core or mandrel may be connected as shown in FIG. 11 where a high pressure line 66 is shown coming from the compressor or other source of air supply with a reducing valve 67 interposed to cut the pressure down in the line 68 leading to the mandrel.

A diflierential pressure valve 69 is connected by pipes 70 and 71 across the high and low pressure sources and is used in the illustration to set off a warning whistle 72 when pressure drops in the supply line to the mandrel.

FIG. 12 shows this differential pressure valve as having large and small cylinders 73, 74 at opposite ends connected with the low and high pressure sources and containing a difierential piston having corresponding large and small ends 75, 76 with the warning whistle connected with the smaller cylinder by a port 77 normally closed by the smaller piston, with the piston upraised in the normal operating position.

With loss of pressure at the low pressure larger end the piston will lower to open port 77 and permit high pressure air to sound the warning signal.

Instead of a whistle, other forms of air operated warning devices may be used or, if desired, controls of various sorts may be utilized to shut down the system when a dangerous drop in pressure occurs.

The cross keys positively connect the core parts together but the lost motion in these connections prevents impact on the drive tubes being directly imparted to the center pipes, while the expansion sleeves provide flexible connection between the center pipes and drive tubes, assisting in holding the parts together but preventing impact on the drive tubes being communicated to the center pipes.

While one-piece split drive tubes may be preferred, because in expanding they retain their cylindrical form and for other reasons, the invention contemplates that these split drive tubes may be made in separate parts, such as semi-cylindrical halves, connected by hinge joints or equivalent to enable them to expand and contract as a substantially cylindrical split tube.

The drive rings between adjoining drive tubes and the drive cap, constituting a form of drive ring, have a substantially continuous circular engagement for applying centered, maximum and uniform driving force.

The transverse keys serve as positive mechanical connections between the drive rings, drive tubes and center pipes with lost motion to allow a desirable amount of independent movement between these par-ts while the expansion sleeves constitute flexible impositive mechanical connections, to some extent cushioning the relation between these parts.

What is claimed is:

1. Concrete pile form comprising the combination of a shell to be driven and left in the earth and a removable core for driving the shell, said core comprising a split drive tube within said shell and having a sleeve of elastic grippingmaterial surrounding the same, expansible into driving engagement with the shell and collapsible to release it from the shell, a center pipe extending down through said drive tube, an expansion sleeve mounted on said center pipe and expansible into pressure applying expanding engagement with said split drive tube and means for supplying expansion fluid to and releasing it from said expansion sleeve, said split drive tube being an integral one-piece spring metal tube having a longitudinal slot in one side, giving it the formation of a split tube and a longitudinal groove in the opposite side providing the effect of a spring hinge for the expansion and contraction of the split drive tube.

2. Concrete pile form comprising the combination of a shell to be driven and left in the earth and a removable core for driving the shell, said core comprising a split drive tube within said shell and having a sleeve of elastic gripping material surrounding the same, expansible into driving engagement with the shell and collapsible to release it from the shell, 2. center pipe extending down through said drive tube, an expansion sleeve mounted on said center pipe and expansible into pressure applying expanding engagement with said split drive tube and means for supplying expansion fluid to and releasing it from said expansion sleeve, said drive tube being an integral one-piece spring metal tube having a longitudinal slot in one side, giving it the formation of a split tube and longitudinally aligned slots in the opposite side arranged with adjoining ends separated by circumferentially continuous spring binge portions.

3. Concrete pile form comprising the combination of a shell to be driven and left in the earth and a removable core for driving the shell, said core comprising a split drive tube within said shell and having -a sleeve of elastic gripping material surrounding the same, expansible into driving engagement with the shell and collapsible to release it from the shell, a center pipe extending down through said drive tube, an expansion sleeve mounted on said center pipe and expansible into pressure applying expanding engagement with said split drive tube, means for supplying expansion fluid to and releasing it from said expansion sleeve, a shell driving shoe engaged by the lower end of the drive tube, a seat in said shoe for centering the lower end of the center pipe and a cushion for the pipe in said seat.

4. Concrete pile form comprising the combination of a shell to be driven and left in the earth and a removable core for driving the shell, said core comprising a split drive tube within said shell and having a sleeve of elastic gripping material surrounding the same, expansible into driving engagement with the shell and collapsible to release it from the shell, a center pipe extending down through said drive tube, an expansion sleeve mounted on said center pipe and expansible into pressure applying expanding engagement with said split drive tube, means for supplying expansion fluid to and releasing it from said expansion sleeve, a drive ring engaged with the upper end of the drive tube and a connecting key extended transversely through said drive ring and center pipe, said center pipe having oversize openings for said key to keep the center pipe free of impact from the drive ring.

5. Concrete pile form comprising the combination of a shell to be driven and left in the earth and a removable core for driving the shell, said core comprising a split drive tube within said shell and having a sleeve of elastic gripping material surrounding the same, expansible into driving engagement with the shell and collapsible to release it from the shell, a center pipe extending down through said drive tube, an expansion sleeve mounted on said center pipe and expansible into pressure applying expanding engagement with said split drive tube, means for supplying expansion fluid to and releasing it from said expansion sleeve, a hammer driven head at the upper end of the core, a drive cap in said head in engagement with the upper end of the drive tube, a driving shoe engaged by the lower end of the drive tube and in driving relation with the shell, a transverse key extending through said drive head, drive cap and center pipe at the upper end of the core and a transverse key extending through said driving shoe and center pipe at the lower end of the core, said transverse keys at the upper and lower ends of the core extending through the center pipe with lost motion enabling movement of the drive tube under hammer blows independent of the center pipe, said key at the upper end of the core having its ends extended beyond the drive head and connections extending therefrom for suspending said drive head, drive cap and center pipe from a power hammer or other support.

6. A concrete'pile form comprising a shell and a removable drive core in said shell, said core including a center pipe, a split drive tube in spaced relation about said center pipe and having a surrounding sleeve of expansible gripping material expansible into engagement with said shell, an expansion sleeve on said center pipe and in communication therewith, said expansion sleeve being in yielding expanding engagement with said split drive tube, a drive ring in engagement with the upper end of said drive tube and a transverse key securing said center pipe and drive ring in connected relation and including lost motion permitting independent relative motion of said drive ring, drive tube and center pipe.

7. A concrete pile form comprising the combination of a shell to be driven and left in the earth and a removable, collapsible core for driving said shell, said core comprising a split drive tube of coextensive circular tube sections hingedly connected by integral reduced wall portions of the tube and having a sleeve of elastic gripping material surrounding the same, said split drive tube being of smaller diameter and located within said shell and said circular sections through the medium of said reduced wall portions yieldingly connecting the same being expansible to carry said gripping material into gripping engagement with the surrounding shell and collapsible to free the drive tube from such gripping relation with the shell, means within said drive tube for effecting expansion and contraction of the same in respect to the surrounding shell, a drive member in driving engagement with the upper end of said split drive tube and a shoe for driving the shell engaged by the lower end of said drive tube, said means for effecting expansion and contraction of the split drive tube being free and clear of said drive member and thereby unafiected by impact of the drive member on said drive tube.

8. A concrete pile form comprising the combination of a shell to be driven and left in the ground and a removable collapsible core for driving the shell, said core comprising an expansible drive tube having a surrounding sleeve of compressible gripping material, within said shell, expansible into driving engagement with the surrounding shell, a drive head in engagement with the upper end of said drive tube, a drive shoe at the lower end of the shell engaged by the lower end of said drive tube, said sleeve of compressible gripping material being contractible to exert collapsing force on said expansible drive tube and expansible by the relatively expansible movement of said drive tube into gripping engagement with the surrounding shell, a center pipe extending down through the center of said drive tube, said pipe being held centered within the drive tube at the upper end by said drive head and at the lower end by said drive shoe by slip connections permitting movement of the drive tube, drive shoe and drive head independent of the pipe and thereby protecting the pipe against impact of hammer blows on the drive head, means at the upper end of said center pipe for admitting pressure fluid into and exhausting it from said center pipe and an elongated flexible elastic annular expansion sleeve mounted in surrounding relation on said center pipe and in pressure applying en- References Cited in the file of this patent UNITED STATES PATENTS Bilyeu Aug. 23, 1910 Gillies Jan. 17, 1922 8 Watt May 3, 1932 McCurdy Nov. 28, 1939 Cobi Mar. 9, 1943 Cortella Nov. 16, 1943 Riemenschneider et al. Mar. 2, 1948 Ellis Mar. 31, 1953 Ricker Apr. 10, 1956 Burrell Apr. 15, 1958 Cobi Apr. 14, 1959 Cobi Apr. 14, 1959 Kupka Feb. 28, 1961 Jourdain Oct. 31, 1961 FOREIGN PATENTS Great Britain Aug. 22, 1956 

